The unemployment rate is down sharply from 8.1 percent a year ago and is at the lowest level since the start of the Great Recession in early 2008, according to figures from the state Employment Development Department. But the rate fell for a worrisome reason: a net of 15,000 county residents left the labor force, many temporarily giving up their search for work.

What’s more, the unemployment rates in the county’s two largest cities, Los Angeles and Long Beach, are still hovering around 8 percent.

California’s unemployment rate continued to improve, falling to 6.2 percent in July from 6.3 percent in June. The national rate stayed steady at 5.3 percent.

Meanwhile, the L.A. County’s payroll job-creating machine hit a major seasonal speed bump in July as the county shed a net 32,600 jobs to fall to a total of 4.28 million.

Public and private education accounted for all of this job loss and then some. The sector fell by 38,400 jobs as substitute teachers and other year-to-year employees saw their jobs end with the school year in June. Many of these teachers and other workers are likely regaining their employment status as the new school year is beginning.

Accounting for this and other seasonal factors, state figures show July’s payroll job loss was even more dramatic, falling by 70,000.

The huge seasonal drop in education was only partially offset by very modest job gains in other sectors, led by leisure/hospitality, which added a net 4,600 payroll jobs. Retail trade added 1,300 jobs.

The picture brightened when looking at the year-over-year jobs figures. Over the past 12 months, the county has gained 108,000 jobs, for a very robust growth rate of 2.6 percent. The biggest gainers were education/health services (up 26,000), trade/transportation (up 21,000) and food service (up 16,000). Manufacturing was the only sector to post a modest decline of 1,300 jobs.